INTERNATIONAL ELECTROTECHNICAL COMMISSION____________ PRIMARY BATTERIES – Part 5: Safety of batteries with aqueous electrolyte FOREWORD 1 The International Electrotechnical Commission
Design
General
Batteries shall be so designed that they do not present a safety hazard under conditions of normal (intended) use.
Venting
All batteries must include a pressure relief mechanism to prevent explosions by managing excessive internal pressure If encapsulation is required to support the cells within the outer casing, the chosen encapsulant and encapsulation method must not lead to overheating during normal use or interfere with the pressure relief function.
The design of the battery case material and its final assembly must ensure that, if one or more cells vent, the battery case itself does not pose any safety hazards.
Insulation resistance
The insulation resistance between externally exposed metal surfaces of the battery excluding electrical contact surfaces and either terminal shall be not less than 5 MΩ at 500 V – + 0 100 V V applied for a minimum of 60 seconds.
Quality plan
Manufacturers must develop and execute a quality plan that outlines the inspection procedures for materials, components, cells, and batteries throughout the manufacturing process of a specific battery type It is essential for manufacturers to comprehend their process capabilities and establish the necessary controls to ensure product safety.
General
Samples should be drawn from production lots in accordance with accepted statistical methods.
Sampling for type approval
The number of samples drawn for type approval is given in Figure 1
NOTE 1 Four batteries connected in series with one of the four batteries reversed (5 sets)
NOTE 2 Four batteries connected in series, one of which is discharged (5 sets)
Figure 1 – Sampling for type approval tests and number of batteries required
General
Applicable safety tests
Applicable safety tests are shown in Table 1
The tests described in Tables 2 and 6 are intended to simulate conditions which the battery is likely to encounter during intended use and reasonably foreseeable misuse
System letter Negative electrode Electrolyte Positive electrode
No letter Zinc (Zn) Ammonium chloride, Zinc chloride
A Zinc (Zn) Ammonium chloride, Zinc chloride
L Zinc (Zn) Alkali metal hydroxide Manganese dioxide (MnO 2 )
P Zinc (Zn) Alkali metal hydroxide Oxygen air
S Zinc (Zn) Alkali metal hydroxide Silver oxide (Ag 2 O)
R: cylindrical (3.5) x: required B: button (3.2) NR: Not required Pr: prismatic single cell (3.12)
Systems L and S button cells or batteries under 250 mAh capacity and system P button cells or batteries under
700 mAh capacity are exempt from any testing.
Cautionary notice
These tests call for the use of procedures which can result in injury if adequate precautions are not taken
It has been assumed in the drafting of these tests that their execution is undertaken by appropriately qualified and experienced technicians using adequate protection.
Ambient temperature
Unless otherwise specified, these tests shall be carried out at an ambient temperature of
Intended use
Intended use tests and requirements
Table 2 – Intended use tests and requirements
Test Intended use simulation Requirements
Electrical test A Storage after partial use No leakage (NL)
Environmental tests B-1 Transportation-shock No leakage (NL)
B-2 Transportation-vibration No leakage (NL)
Climatic-temperature C Climatic-temperature cycling No fire (NF)
Intended use test procedures
6.2.2.1 Test A – Storage after partial use a) Purpose
This test replicates the scenario where an appliance is turned off with partially discharged batteries These batteries may either remain in the appliance for an extended period or be removed and stored for a long time.
An undischarged battery is discharged under an application/service output test condition, with the lowest resistive load test as defined in IEC 60086-2 until the service life falls by
50 % of the minimum average duration (MAD) value, followed by storage at 45 °C ± 5 °C for 30 days c) Requirements
There shall be no leakage, no fire and no explosion during this test
This test simulates the situation when an appliance is carelessly dropped with batteries installed in it This test condition is generally specified in IEC 60068-2-27 b) Test procedure
An undischarged battery shall be tested as follows
The shock test shall be carried out under the conditions defined in Table 3 and the sequence in Table 4
Shock pulse – The shock pulse applied to the battery shall be as follows:
Minimum average acceleration first three milliseconds Peak acceleration
Step Storage time Battery orientation Number of shocks Visual examination periods
6 – – – Post-test a The shock shall be applied in each of three mutually perpendicular directions
Step 1 Record open circuit voltage in accordance with 5.2
Steps 2 to 4 Apply shock test specified in Table 3 and the sequence in Table 4
Step 6 Record examination results c) Requirements
There shall be no leakage, no fire and no explosion during this test
This test simulates vibration during transportation This test condition is generally specified in IEC 60068-2-6 b) Test procedure
An undischarged battery shall be tested as follows
The vibration test shall be carried out under the following test conditions and the sequence in Table 5
The battery will undergo simple harmonic motion with a vibration amplitude of 0.8 mm and a total maximum excursion of 1.6 mm The frequency will be adjusted at a rate of 1 Hz per minute, ranging from 10 Hz to 55 Hz The complete frequency range, from 10 Hz to 55 Hz and back to 10 Hz, will be traversed in a duration of 90 ± 5 minutes for each mounting position.
Step Storage time Battery orientation Vibration time Visual examination periods
6 – – – Post-test a The vibration shall be applied in each of three mutually perpendicular directions
Step 1 Record open circuit voltage in accordance with 5.2
Steps 2 to 4 Apply the vibration specified in 6.2.2.3 in the sequence in Table 5
Step 6 Record examination results c) Requirements
There shall be no leakage, no fire and no explosion during this test
6.2.2.4 Test C – Climatic-temperature cycling a) Purpose
This test assesses the integrity of the battery seal which may be impaired after temperature cycling b) Test procedure
An undischarged battery shall be tested under the following procedure
Temperature cycling procedure (see 1) to 7) below and/or Figure 2)
1) Place the batteries in a test chamber and raise the temperature of the chamber to
2) Maintain the chamber at this temperature for t 2 = 4 h
3) Reduce the temperature of the chamber to 20 °C ± 5 °C within t 1 = 30 min and maintain at this temperature for t 3 = 2 h
4) Reduce the temperature of the chamber to –20 °C ± 5 °C within t 1 = 30 min and maintain at this temperature for t 2 = 4 h
5) Raise the temperature of the chamber to 20°C ± 5 °C within t 1 = 30 min
6) Repeat the sequence for a further nine cycles
7) After the 10 th cycle, store the batteries for seven days prior to examination t 1 = 30 min t 2 = 4 h t 3 = 2 h
Figure 2 – Temperature cycling procedure c) Requirements
There shall be no fire and no explosion during this test.
Reasonably foreseeable misuse
Reasonably foreseeable misuse tests and requirements
Table 6 – Reasonably foreseeable misuse tests and requirements
Electrical tests D Incorrect installation No fire (NF)
E External short circuit No fire (NF)
Environmental test G Free fall No fire (NF)
Reasonably foreseeable misuse test procedures
6.3.2.1 Test D – Incorrect installation (four batteries in series) a) Purpose
This test simulates the condition when one battery in a set is reversed b) Test procedure
Four undischarged batteries of identical brand, type, and origin are to be connected in series, with one battery (B1) reversed, as illustrated in Figure 3 The circuit must remain active for 24 hours or until the temperature of the battery case returns to ambient levels.
The resistance of the inter-connecting circuitry shall not exceed 0,1 Ω.
Figure 3 – Circuit diagram for incorrect installation (four batteries in series)
NOTE 1 The circuit in Figure 3 simulates a typical misuse condition
NOTE 2 Primary batteries are not designed to be charged However, reversed installation of a battery in a series of three or more exposes the reversed battery to a charging condition Although cylindrical batteries are designed to relieve excessive internal pressure, in some instances an explosion may not be precluded c) Requirements
There shall be no fire and no explosion during this test (see NOTE 2 of 6.3.2.1b))
6.3.2.2 Test E – External short circuit a) Purpose
This misuse may occur during daily handling of batteries b) Test procedure
To properly connect an undischarged battery, follow the configuration illustrated in Figure 4 Ensure the circuit remains active for 24 hours or until the battery case temperature stabilizes to ambient levels Additionally, the resistance of the interconnecting circuitry must not exceed 0.1 Ω.
Figure 4 – Circuit diagram for external short circuit c) Requirements
There shall be no fire and no explosion during this test
This test simulates the condition when one (1) discharged battery is series-connected with three (3) other undischarged batteries b) Test procedure
An undischarged battery (C1) is tested under service output conditions until its on-load voltage drops to \(n \times 0.6 \, V\), where \(n\) represents the number of cells in the battery, following the highest MAD value as per IEC 60086-2 Subsequently, three undischarged batteries and one discharged battery (C1) of the same brand, type, and origin are connected in series The discharge process continues until the total on-load voltage reaches four times \(n \times 0.6 \, V\).
The resistor value (R1) should be roughly four times the minimum value determined from the resistive load tests outlined for the battery in IEC 60086-2 Ultimately, the final resistor value (R1) must align closely with the specifications provided in section 6.4 of IEC 60086-1:2015.
Figure 5 – Circuit diagram for overdischarge c) Requirements
There shall be no fire and no explosion during this test
6.3.2.4 Test G – Free fall test a) Purpose
This test simulates the situation when a battery is accidentally dropped The test condition is based upon IEC 60068-2-31 b) Test procedure
Undischarged test batteries must be dropped from a height of 1 meter onto a concrete surface Each battery is subjected to six drops: a prismatic battery is dropped once on each of its six faces, while a round battery is dropped twice along each of its three axes After the drops, the test batteries should be stored for one hour.
Figure 6 – XYZ axes for free fall c) Requirements
There shall be no fire and no explosion during this test
Precautions during handling of batteries
Proper use of primary batteries with aqueous electrolytes ensures a safe and reliable power source Misuse or abuse of these batteries can lead to leakage, and in severe cases, may cause fire or explosion Always ensure that batteries are inserted correctly, paying attention to the marked polarities (+ and -) on both the battery and the device.
Incorrectly placed batteries in equipment can lead to short-circuiting or overcharging, resulting in rapid temperature increases that may cause venting, leakage, explosions, and personal injury It is crucial to avoid short-circuiting batteries to ensure safety.
Short-circuiting occurs when the positive and negative terminals of a battery come into contact, which can happen with loose batteries in pockets or handbags alongside keys or coins This dangerous situation can lead to venting, leakage, explosions, and potential personal injury.
IEC z x y c) Do not charge batteries
Attempting to charge a non-rechargeable (primary) battery may cause internal gas and/or heat generation resulting in venting, leakage, explosion and personal injury d) Do not force discharge batteries
Force discharging batteries with an external power source can lower their voltage beyond design limits, leading to gas generation, which poses risks of venting, leakage, explosions, and personal injury Additionally, it is crucial to avoid mixing old and new batteries or using batteries of different types or brands.
When replacing batteries, replace all of them at the same time with new batteries of the same brand and type
Using batteries of different brands or types, or mixing new and old batteries, can lead to over-discharging due to variations in voltage or capacity This poses risks such as venting, leakage, and potential explosions, which may result in personal injury Therefore, it is crucial to promptly remove exhausted batteries from devices and dispose of them properly.
When discharged batteries are kept in the equipment for a long time, electrolyte leakage may occur causing damage to the appliance and/or personal injury g) Do not heat batteries
When a battery is exposed to heat, venting, leakage and explosion may occur and cause personal injury h) Do not weld or solder directly to batteries
The heat from welding or soldering directly to a battery may cause internal short-circuiting resulting in venting, leakage and explosion and may cause personal injury i) Do not dismantle batteries
When a battery is dismantled or taken apart, contact with the components can be harmful and may cause personal injury or possibly fire j) Do not deform batteries
Batteries should not be crushed, punctured, or otherwise mutilated Such abuse may result in venting, leakage and explosion and cause personal injury k) Do not dispose of batteries in fire
Improper disposal of batteries in fire can lead to dangerous explosions and personal injuries It is crucial to only incinerate batteries in approved, controlled incinerators Additionally, always keep batteries out of the reach of children to ensure safety.
Keep swallowable batteries out of children's reach, especially those that fit within the ingestion gauge limits shown in Figure 7 If a cell or battery is ingested, seek medical assistance immediately.
1 Numbers in square brackets refer to the bibliography
Figure 7 – Ingestion gauge m) Do not allow children to replace batteries without adult supervision n) Do not encapsulate and/or modify batteries
Modifying a battery, including encapsulation, can obstruct the pressure relief vent and hinder the release of hydrogen gas, potentially causing explosions and personal injury It is crucial to consult the battery manufacturer before making any modifications Additionally, store unused batteries in their original packaging and keep them away from metal objects; if unpacked, avoid mixing or jumbling the batteries.
To prevent battery short-circuiting, which can lead to venting, leakage, explosions, and personal injury, it is crucial to store unused batteries in their original packaging Additionally, remove batteries from devices that will not be used for an extended period, except in emergency situations.
To prevent potential leakage, it is beneficial to promptly remove batteries from equipment that is no longer functioning properly or when extended periods of inactivity are expected, such as with portable lighting and toys Despite the protective jackets on most batteries today, those that are partially or fully depleted are at a higher risk of leaking compared to unused batteries.
Packaging
Proper packaging is essential to prevent mechanical damage during transport, handling, and stacking The selection of materials and packaging design must ensure that unintentional electrical contact, short-circuits, terminal corrosion, and environmental exposure are effectively mitigated.
Handling of battery cartons
Battery cartons should be handled with care Rough handling might result in battery damage This can cause leakage, explosion, or fire.
Display and storage
a) Batteries shall be stored in well-ventilated, dry and cool conditions
High temperature or high humidity may cause deterioration of the battery performance or surface corrosion
+0,1 25,4 0 +0,1 57,1 0 b) Battery cartons should not be piled up in several layers (or should not exceed a specified height)
Excessive stacking of battery cartons can lead to deformation and electrolyte leakage in the lower cartons Batteries should be stored in warehouses or displayed in retail environments away from direct sunlight and moisture to prevent decreased insulation resistance, self-discharge, and rust formation Additionally, it is important to avoid mixing unpacked batteries to prevent mechanical damage and short-circuiting.
Mixing batteries can lead to physical damage or overheating due to external short circuits, potentially resulting in leakage or explosions To prevent these hazards, it is essential to keep batteries in their original packaging until they are needed For more information, refer to Annex A.
Transportation
To ensure safe transportation of battery packages, they must be arranged to minimize the risk of falling, avoiding stacking one on top of another Additionally, packages should not be stacked excessively high to prevent damage to those at the bottom It is also essential to provide protection from adverse weather conditions.
Disposal
When handling batteries, it is crucial to avoid dismantling them and to refrain from disposing of them in fire, except in controlled incineration settings Primary batteries can typically be disposed of through communal refuse systems, unless local regulations state otherwise Additionally, if there are designated collection points for used batteries, these should be utilized for proper disposal.
• Store collected batteries in a non-conductive container
Store used batteries in a well-ventilated area to prevent the risk of hydrogen gas buildup, which can occur due to residual charges in the batteries Proper ventilation is essential, as inadequate airflow can lead to dangerous conditions where hydrogen gas may accumulate and potentially explode if exposed to an ignition source.
Do not combine collected batteries with other materials, as they may still hold a residual charge This can lead to short circuits, charging, or forced discharges, which may generate heat Such heat can ignite flammable materials like oily rags, paper, or wood, posing a fire risk.
To prevent short circuits, charging issues, and force discharging in high-voltage batteries, it is essential to protect used battery terminals One effective method is to cover the terminals with insulating tape.
• Failure to observe these recommendations may result in leakage, fire, and/or explosion
To ensure optimal performance and safety, always choose the appropriate size and grade of battery for your equipment, retaining any provided information for future reference Replace all batteries in a set simultaneously and clean both the battery contacts and the equipment before installation Make sure to install the batteries with the correct polarity (+ and -) and remove them from devices that will not be used for an extended period Additionally, promptly dispose of exhausted batteries to maintain equipment efficiency.
General (see Table 7)
All batteries, except for small ones, must display essential information, including their designation (either IEC or common), the expiration date or the year and month/week of manufacture (which may be coded), the polarity of the positive (+) terminal, the nominal voltage, the manufacturer's or supplier's name or trademark, and any cautionary advice.
NOTE The common designation can be found in Annex D of IEC 60086-2.
Marking of small batteries (see Table 7)
Small batteries classified as category 3 and category 4 by the IEC have limited surface area for markings, requiring only designation 9.1 a) and polarity 9.1 c) to be marked directly on the battery Additional markings specified in 9.1 can be placed on the immediate packaging For P-system batteries, designation 9.1 a) can appear on the battery, sealing tab, or packaging, while polarity 9.1 c) may be marked on the sealing tab and/or the battery Other markings, including 9.1 b), 9.1 d), and 9.1 e), should be provided on the immediate packaging It is also essential to include a caution regarding the ingestion of swallowable batteries, as detailed in section 7.1 l).
Marking Batteries with the exception of small batteries
P-system batteries are designated by IEC standards or common labels such as A, A, and C It is important to note the expiration of the recommended usage period, which is indicated by the year and month or week of manufacture, often represented in code.
A B B c) Polarity of the positive (+) terminal A A D d) Nominal voltage A B B e) Name or trade mark of the manufacturer or supplier A B B f) Cautionary advice A B a B a
A: shall be marked on the battery
B: may be marked on the immediate packing instead on the battery
C: may be marked on the battery, the sealing tab or the immediate packing
D: may be marked on the sealing tab and/or on the battery a Caution for ingestion of swallowable batteries shall be given Refer to 7.1 l).
Safety pictograms
Safety pictograms that could be considered for use as an alternative to written cautionary advice are provided in Annex C
Additional information on display and storage
This annex aims to outline best practices for the display and storage of batteries, while also highlighting procedures that have proven to be detrimental It serves as guidance for battery manufacturers, distributors, users, and equipment designers.
For optimal battery storage, maintain a temperature between +10 °C and +25 °C, avoiding extremes above +30 °C and humidity levels over 95% RH or below 40% RH, as these conditions can harm both batteries and packaging Batteries should not be placed near heat sources or in direct sunlight While room temperature storage is effective, lower temperatures can enhance storage life if batteries are kept in protective packing to prevent condensation during warming Cold-stored batteries should be used promptly after reaching ambient temperature Batteries may be stored in equipment if approved by the manufacturer, and stacking height should not exceed 1.5 m for cardboard packs or 3 m for wooden cases These storage guidelines also apply during transit; batteries should be kept away from ship engines and not left in unventilated metal containers during hot weather Prompt dispatch after manufacture and proper stock rotation practices (first-in, first-out) are essential, requiring well-designed storage areas and clear labeling.
Background
General
To keep pace with advancements in battery-powered technology, primary batteries have evolved in both chemistry and design, leading to enhanced capacity and performance Ongoing developments highlight the importance of safety and optimal battery functionality, as most reported battery failures stem from electrical abuse, often due to accidental consumer misuse.
The following text and figures are intended to aid the battery-powered equipment designer to significantly reduce or eliminate such battery failures.
Battery failures resulting from poor battery compartment design
Poor battery compartment design may lead to reversed battery installation or to short- circuiting of the batteries.
Potential hazards resulting from battery reversal
If a battery is reversed in a circuit with three or more batteries in series as shown in Figure B.1, the following potential hazards exist: a) charging of the reversed battery;
NOTE The charging current limited by the external circuit/load b) gas generation within the reversed battery; c) vent activation of the reversed battery; d) leakage of electrolyte from the reversed battery
NOTE Battery electrolytes are harmful to body tissues
Figure B.1 – Example of series connection with one battery reversed
Potential hazards resulting from a short circuit
a) Heat generation resulting from high current flow b) Gas generation
Reversed battery c) Vent activation d) Electrolyte leakage e) Heat damage to insulating jackets (e.g shrinkage)
NOTE Battery electrolytes are harmful to body tissues and generated heat can cause burns.
General guidance for appliance design
Key battery factors to be first considered
These guidelines focus on cylindrical batteries sized R1 to R20, specifically alkaline manganese and zinc carbon systems Although these two battery types are interchangeable, they must not be used together.
When designing battery compartments, it is crucial to consider the physical differences and design features of alkaline manganese and zinc carbon batteries The positive terminal of the alkaline manganese battery is connected to its case, while the zinc carbon battery's positive terminal is insulated Both types feature an outer insulated jacket made of non-conductive materials, although some may have a metallic jacket that is insulated from the battery unit Additionally, the negative contact should account for potentially recessed battery terminals, and flat negative equipment contacts should be avoided to ensure good electrical contact Importantly, battery connectors and any part of the equipment circuitry must not touch the battery jacket to prevent the risk of short circuits.
When using conical or helical springs for negative connections, it is essential that they compress uniformly upon battery insertion and do not make contact with the battery jacket Additionally, connecting springs to the positive terminal of a battery is not advisable.
Other important factors to consider
To ensure optimal performance and safety in battery-powered equipment, companies should collaborate closely with the battery industry, considering existing battery capabilities from the design phase and selecting batteries compliant with IEC 60086-2 Battery compartments must be designed for easy insertion while preventing accidental removal and restricting access for young children It is crucial to avoid tying dimensions to specific battery manufacturers to facilitate compatibility with various replacements, adhering only to IEC 60086-2 specifications Clear labeling of battery type, polarity, and insertion directions is essential Despite advancements in leakage resistance, precautions should be taken to minimize equipment damage from potential battery leakage by strategically positioning the battery compartment Additionally, the equipment circuitry should be designed to prevent operation below 0.7 V per battery to avoid adverse chemical reactions that could lead to leakage.
Specific measures against reversed installation
General
To address issues related to the incorrect installation of batteries, it is essential to incorporate design features that prevent improper placement or ensure that incorrect installations do not create electrical contact.
Design of the positive contact
Figures B.2 and B.3 illustrate recommendations for R03, R1, R6, R14, and R20 size battery compartments It is essential to ensure that batteries are secured to prevent unnecessary movement within the compartment Additionally, battery contacts should be shielded to avoid accidental contact during reverse installation.
Figure B.2a – Correct insertion of the battery Figure B.2b – Incorrect insertion of the battery
Figure B.2 – Positive contact recessed between ribs
Figure B.3a – Correct insertion of the battery Figure B.3b – Incorrect insertion of the battery
Figure B.3 – Positive contact recessed within surrounding insulation
Design of the negative contact
The following suggestion is given for R03, R1, R6, R14 and R20 size battery compartments (see Figure B.4)
Insulated ribs hold the negative terminal away from contact
Negative terminal contacts only the insulated surround
Figure B.4a – Correct insertion of the battery Figure B.4b – Incorrect insertion of the battery
Figure B.4 – Negative contact U-shaped to ensure no positive (+) battery contact
Design with respect to battery orientation
In order to avoid reverse insertion of batteries, it is recommended that all batteries have the same orientation Examples are shown in Figures B.5a and B.5b
Figure B.5a shows the preferred battery arrangement inside a device while Figure B.5b shows an alternative recommendation
NOTE Protection of the positive contact is as shown in Figures B.2 and B.3
NOTE 1 Protection of the contacts is in Figures B.2 or B.3 for the positive and Figure B.4 for the negative contact
NOTE 2 This arrangement (Figure B.5b) is only considered practical for R14 and R20 size batteries due to the small negative terminal area (dimension C of the relevant specification) of the other sizes
Figure B.5b – Alternative recommendation for battery orientation
Figure B.5 – Design with respect to battery orientation
Positive terminal does not contact U-shaped negative contact but only insulated centre
Dimensional considerations
Table B.1 outlines essential dimensional specifications for battery terminals and the recommended size for the device's positive contact By consulting Figure B.6 and adhering to the dimensions in Table B.1, a battery can be designed to prevent electrical contact when reversed, ensuring a 'fail safe' condition where the negative terminal does not connect with the device's positive contact.
Table B.1 – Dimensions of battery terminals and recommended dimensions of the positive contact of an appliance in Figure B.6
Relevant dry batteries Dimension of the negative battery terminal
Dimension of the positive battery terminal Recommended dimensions of the positive contact of an appliance in Figure B.6 d 6 a
R1, LR1 5,0 4,0 0,5 4,1 to 4,9 0,1 to 0,4 a Refer to IEC 60086-2
Figure B.6a – Correct insertion Figure B.6b – Incorrect insertion
NOTE Positive contact of an appliance is recessed within surrounding insulation
Figure B.6 – Example of the design of a positive contact of an appliance
Negative contact of an appliance
Positive contact of an appliance
Negative contact of an appliance
Positive contact of an appliance d 6
The recessed hole's diameter is larger than the positive battery terminal (d 3 ) but smaller than the negative terminal (d 6 ) Figure B.6a illustrates the correct insertion of the battery, while Figure B.6b demonstrates an incorrect reverse insertion, where the negative terminal only contacts the surrounding insulation, preventing electrical contact.
The letter codes in Figure B.6 indicate the following: \(d_6\) represents the minimum outer diameter of the negative flat contact surface, \(d_3\) denotes the maximum diameter of the positive contact within the specified projection height, and \(h_3\) signifies the minimum projection of the flat positive contact.
X Diameter of the recessed hole as a positive contact with the positive battery terminal X should be bigger than d 3 but smaller than d 6 ;
Y Depth of the recessed hole as a positive contact with the positive battery terminal
Specific measures to prevent short-circuiting of batteries
Measures to prevent short-circuiting due to battery jacket damage
In alkaline manganese batteries, the steel case shares the same voltage as the positive terminal and is protected by an insulating jacket If this jacket is compromised by conductive circuitry, a short circuit may result, especially if the appliance experiences physical abuse such as abnormal vibrations or drops.
NOTE 1 The potential hazards resulting from a short circuit are defined in B.1.3
NOTE 2 Whilst the example shown in Figure B.7 commonly relates to alkaline manganese battery systems, the batteries addressed in this annex are interchangeable (see B.2.1)
Figure B.7 – Example of a short circuit, a switch is piercing the battery insulating jacket
Prevention: insulating material positioned as shown in Figure B.8 prevents the switch from damaging the battery jacket
Figure B.8 – Typical example of insulation to prevent short circuit
It is crucial to ensure that no components of the equipment, including rivets or screws used to secure battery contacts, come into contact with the battery case or jacket.
Measures to prevent external short-circuit of a battery caused when
spring contacts are employed for battery connection
Inserting a battery with the positive (+) end facing forward, as illustrated in Figure B.9, can lead to distortion of the negative (–) spring contact This distortion may cause the spring to cut and pierce the battery's insulating jacket, as demonstrated in Figure B.10.
Figure B.9 – Insertion against spring (to be avoided)
Figure B.10a – Spring slides underneath the jacket and contacts the metal can Figure B.10b – Jacket is punctured
Figure B.10 – Examples showing distorted springs
To prevent potential incidents illustrated in Figure B.10, it is essential to design the battery compartment so that the battery, when inserted correctly with the negative terminal first, evenly compresses the coil spring as depicted in Figure B.11 The insulated guide above the negative (–) connections, as shown in Figure B.11, facilitates this proper alignment.
Figure B.11 – One example of protected insertion
To ensure safety and prevent damage, the end of the spring coil that contacts the battery should be bent towards the center, avoiding any sharp edges that could harm the battery jacket.
The diameter of the spring wire must meet the specifications outlined in Table B.2 It is crucial for the spring contact pressure to be adequate to ensure reliable electrical contact with the batteries at all times, while also allowing for easy insertion and removal Excessive pressure can lead to damage, such as cutting or piercing of the insulating jacket and deformation of the contacts.
This can lead to a short circuit and/or leakage
Table B.2 contains details on the recommended diameters of the spring wire
Spring coil contacts should only contact the negative terminals of cylindrical batteries
Battery type Minimum wire diameter mm
Special considerations regarding recessed negative contacts
IEC 60086-2 outlines the maximum allowable recess for the negative battery terminal from the external jacket Numerous R20, LR20, R14, and LR14 batteries feature a recessed negative terminal Additionally, some batteries incorporate insulating resin projections on the negative terminal to prevent electrical contact in the event of battery reversal.
When designing the negative contact of an appliance, it is crucial to consider the shapes and dimensions of negative battery terminals There are three main types of contacts to keep in mind: First, if using a spring coil, its diameter must be smaller than \(d_6\), the external diameter of the battery terminal's contact surface Second, for sheet metal contacts, dimensions \(h_4\) and \(d_6\) must be adhered to, and a projection or pip should be included to ensure proper contact, overcoming any recess in the battery terminal Lastly, when utilizing a flat metal plate as the negative contact, it is vital to incorporate one or more projections that are deep enough to address any recess in the terminal and fit within the contact area defined by \(d_6\).
Figure B.12a – Spring coil Figure B.12b – Plate spring contact
Figure B.12 – Example of negative contacts Table B.3 – Dimensions of the negative battery terminal
Battery type Maximum recessed dimension of negative battery terminal h 4 a mm
External diameter of the contact surface of negative battery terminal d 6 a mm
It is crucial to ensure that battery compartment dimensions are not solely based on the specifications and tolerances of a specific manufacturer, as this may lead to issues when installing replacement batteries from different sources.
For dimensional specifications concerning the positive and negative terminals, please refer to Figures 1a and 1b in IEC 60086-2:2015, along with the pertinent battery specifications outlined in IEC 60086-2.
Waterproof and non-vented devices
To prevent the risk of explosion in devices using batteries, it is crucial to either eliminate the hydrogen gas produced through a recombination reaction or allow it to vent Failure to do so may lead to ignition of the trapped hydrogen/air mixture Therefore, consulting the battery manufacturer during the design phase of these applications is essential.
Other design considerations
To ensure safety and efficiency, only the battery terminals should make physical contact with the electric circuit, while battery compartments must be electrically insulated and strategically positioned to reduce the risk of damage or injury from battery leakage Additionally, many devices are engineered to function with alternative power sources, such as mains or supplementary batteries, which is especially important for primary battery memory backup applications Therefore, the equipment's circuitry should be designed accordingly.
1) prevent charging of the primary battery, or
To ensure the safety and longevity of primary batteries, it is essential to incorporate protective devices, such as diodes These devices prevent reverse charging currents from exceeding the limits set by the battery manufacturer, thereby safeguarding the battery's performance and integrity.
When selecting a protective device circuit for a primary battery, it is crucial to choose one that aligns with the specific type and electrochemical system of the battery, ensuring it is resilient against single component failures Equipment designers are advised to consult with the battery manufacturer for guidance on the appropriate memory back-up protection device circuit.
Neglecting safety precautions can result in reduced battery life, leakage, or even explosions To prevent confusion during battery installation, ensure that positive (+) and negative (–) contacts are distinctly shaped Choose terminal contact materials that exhibit low electrical resistance and are compatible with battery contacts Battery compartments must be non-conductive, heat-resistant, non-flammable, and capable of effective heat dissipation without deforming when batteries are inserted Equipment using air-depolarised batteries from the A or P system should allow sufficient air access, with A system batteries ideally positioned upright during operation Parallel connections in battery compartments are not allowed unless safety can be assured despite potential battery reversal Additionally, avoid series connections of batteries with varying voltage outputs, as this may lead to reverse voltage issues in discharged sections.
Example in Figure B.13, two batteries are discharging through resistor R1; if, following their discharge, the switch is positioned toward the R3 circuit, forced discharging of the former two batteries may occur
Figure B.13 – Example of series connection of batteries with voltage tapping
Potential hazards arising from forced discharging (driving into reverse voltage)
1) Gas generation within the forced discharged battery/batteries
NOTE Battery electrolytes are harmful to body tissues
General
Historically, cautionary advice for meeting marking requirements has been provided through written text However, there is an increasing trend in recent years towards using pictograms as a complementary or alternative method for communicating product safety information.
This annex aims to create standardized pictogram recommendations linked to established written text, reduce the variety of safety pictogram designs, and promote the use of pictograms over written text for conveying product safety and cautionary information.
Pictograms
The pictogram recommendations and cautionary advices are given in Table C.1
DO NOT DISPOSE OF IN FIRE
NOTE The grey shading highlights a white margin appearing when the pictogram is printed on coloured or black background
NOTE Under consideration to replace pictogram E
KEEP OUT OF REACH OF CHILDREN NOTE See 7.1 l) for critical safety information
F DO NOT MIX DIFFERENT TYPES OR BRANDS
G DO NOT MIX NEW AND USED
NOTE The grey shading highlights a white margin appearing when the pictogram is printed on coloured or black background
Recommendations for use
To ensure effective use of pictograms, they must be clearly legible and should utilize colors that enhance rather than obscure the displayed information Specifically, when colors are applied, pictogram J should feature a blue background, while the circle and diagonal bar of other pictograms should be red Additionally, it is important to note that not all pictograms are required to be used simultaneously for a specific type or brand of battery.
In particular, pictograms D and J are meant as alternatives for a similar purpose
[1] IEC 60086-3, Primary batteries – Part 3: Watch batteries
[2] IEC 60086-4, Primary batteries – Part 4: Safety of lithium batteries
[3] ISO/IEC Guide 50: 2015, Safety aspects – Guidelines for child safety
[4] ISO/IEC Guide 51:2014, Safety aspects – Guidelines for their inclusion in standards
[5] IEC 60050-482:2004, International Electrotechnical Vocabulary – Part 482: Primary and secondary cells and batteries
[6] ISO 8124-1, Safety of toys – Part 1: Safety aspects related to mechanical and physical properties